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By Richard Frentress, Dave Donelon, Robert Henderson, Mike Warnert

"The Round Mountain gold mine is an open-pit mining operation located 97 kilometres north of Tonopah in Nye County, Nevada. Gold has been produced from the property since 1906.Gold is currently recovered using a combination of four independent processing operations. These include a 10,000 ton per day mill, a 30,000 ton per day, crushed ore heap leach, a 150,000 ton per day, run-of-mine ore heap leach and a small high-grade gravity concentration circuit. In 2002, Round Mountain Gold Corporation produced 755,494 troy ounces of gold at a total direct operating cost of US$2.14 per ton ($193/oz).This paper presents a summary of the Round Mountain operations and discusses some of the processing innovations that have enabled the mine to profitably recover gold from a large low-grade ore body.INTRODUCTIONRound Mountain Gold Corporation is a 50/50 joint venture between Kinross Gold Corporation and Barrick Gold Corporation. Kinross acquired its ownership interest in the Round Mountain mine upon completion of combination with Echo Bay on January 31, 2003. The joint venture partners continue to support an aggressive exploration program in the vicinity of the mine in order to add reserves and extend the mine life.The Round Mountain mine currently operates a conventional open pit that is approximately 8,200 feet long, 4,900 feet wide and 980 feet deep. Mining is conducted on 34-metre benches by electric shovels and front-end loaders paired with 150, 190 and 240-ton haul trucks. Blasthole samples are collected and assayed and provide the control for ore segregation. Based upon these assays, blasted pit rock is determined to be run-of-mine Dedicated Pad ore, crushed Reusable Pad ore, high-grade ore or waste.Gold is recovered using a combination of four independent processing operations. These include run-of-mine ore heap leaching (Dedicated Pad), crushed ore heap leaching (Reusable Pad), milling and the gravity concentration circuit. Non-mineralised rock is delivered directly to the waste dumps. Low-grade ore is trucked directly to the Dedicated Pad and medium-grade ore is crushed and placed on the Reusable Pad. High-grade ore is handled in one of three ways: 1) leached on the Reusable Pad and offloaded to the mill; 2) sent directly to the gravity plant with tails reporting to the mill; or 3) sent directly to the mill or mill stockpile. The gold particle size distribution of highgrade ore determines the processing method."

Jan 1, 2005

By Colin P. Pigott

The paper describes a variety of existing techniques and equipment which when combined together permit faster and cheaper drilling of shafts in soft to medium strength formations. Drilling fluid circulation, methods of hole stabilisation and bit design, including the advantages of flat bottomed and conical bits, shrouds and skirts, tungsten carbide, long tooth and disc cutters are considered. The principles of rock chip transportation and bottom hole cleaning are described together with a new and very efficient fluid circulation system which was invented by the author.

Jan 1, 1985

By Horst Huettenhain

The Rowland Coal Preparation Plant is located on Workman's Creek in Raleigh County, West Virginia, approximately 20 miles Northwest of Beckley and 10 miles Southeast of Ameagle. It is owned and operated by the Rowland Division of Consolidation Coal Company. This paper describes the plant flowsheet, process considerations that were evaluated in its development, and observations made during and since the plant was constructed. The final flowsheet was developed specifically to wash the coal from the Rowland Mine and contains several equipment combinations and applications heretofore never placed in a single, commercial operation. The major process equipment is presented in a functional description of the flowsheet. The coal reserves are leased from the Rowland Land Company and consist primarily of #2 Gas and Middle Eagle coals and various major splits of the Middle Eagle seam. The Rowland Coal Preparation Plant was designed to process 560 TPH of raw coal consisting of 50 percent #2 Gas coal intimately mixed with 50 percent Middle Eagle coal and containing lumps no larger than a 12-inch cube.

Jan 1, 1970

By J M. F Clout

The Roy Hill Project is an independent integrated port, rail and mine development in the Pilbara region of Western Australia. The bankable feasibility study for the project was completed in January 2011 by Roy Hill Holdings Pty Ltd, a wholly owned subsidiary of Hancock Prospecting Pty Ltd. The Project will deliver 55 Mt/a of premium quality iron ore to a rapidly growing market with a mine life of over 27 years. This study is based on exploiting a 1.2 Bt bedded resource of microplaty haematite-rich Marra Mamba, from which 562 Mt of reserves has been delineated to date. A further 1.1 Bt resource of detritals and low grade bedded is proposed to be mined once the bedded high grade resource is depleted. Roy Hill lump and fi ne ore products will compete strongly with other Pilbara products. As a low cost producer, Roy Hill is on track to capture four per cent of the global seaborne traded iron ore market. The project decision to proceed is targeted for Q2 2011 to enable first ore on ship by Q2 2014.

Jul 11, 2011

By Henry Louis

THE work performed by the Royal Commission on Mining Subsidence is likely to prove of permanent value, less perhaps for the conclusions it has reached and for the recommendations it has based upon these than for the admirable exposition which it affords of the law concerning mining subsidence and of the legal status of the person who has suffered damage by reason of such subsidence, as also of him whose working has caused the damage. The Commission was appointed by Royal Warrant in the middle of 1925 and delivered its final report in the middle of 1927. The terms of reference to the Commission were as follows: "To consider the operation of the law relating to the support of the surface of the land, and of buildings or works on or under the surface, by underlying or adjacent minerals; to enquire into the extent and gravity of the damage caused by subsidence owing to the extraction of minerals and the incidence of the resulting liability; and to report what steps should be taken, by legislation or otherwise, to remedy, equitably to all persons concerned, any defects or hardships that may be found to arise in existing conditions."

Jan 1, 1929

The Río Agrio of northern Patagonia, Argentina, is highly acidic due to inputs of volcanic gases (SO2, HCl, HF) in its headwaters. The watershed includes a hyper-acidic (pH <0.5) volcanic crater lake, a larger glacially carved lake that is also strongly acidic (pH 2.6 to 2.7) and an acidic river that flows for more than 40 km (25 miles) before its pH is completely neutralized. This unique watershed has many geochemical and biological similarities to acid waters caused by mining. This paper describes the Río Agrio watershed and draws a comparison with some famous acid mine waters. Learning more about naturally acidic lakes and river systems could have important applications to the bioleaching of ores or biological treatment of mine waters. Therefore, it should be of interest to the general community of mining and metallurgical engineers.

Jan 1, 2008

By Norman Marr

Introduction In Canada, the mining industry and water-power development are intimately associated in that mining, which ranks second among the country&apos;s primary industries, depends principally upon hydro-electric energy for its large power requirements. On the whole, the Dominion has been very favourably endowed with water-power resources; generally speaking it is a well-watered country with numerous rivers and lakes located in are as where the topography favours water-power development. Precipitation, the raw material of water power, varies from an annual fall of more than l00 inches on the Pacific coast to about 12 inches in sections of the Prairies and the Northwest Territories; in Ontario and Quebec the annual average is 24 to 40 inches and in Nova Scotia about 45 inches. In its descent to the sea, the resulting run-off, much of it from considerable altitudes, creates sources of potential energy at every rapid and fall along the country&apos;s many streams and rivers. Many of the innumerable lakes in the Dominion provide storage basins for the regulation of stream flow, thus enhancing the potential power of available sites. While water-power resources are fairly well distributed across the Dominion, as is shown on the accompanying map of Canada showing power sites (Figure 1), it is particularly fortunate that those areas which are lacking in indigenous fuels have been compensated in large degree for this scarcity by being favoured with a high proportion of the total potential water power. This has an important bearing on the mining industry in that extensive mining operations can be economically carried out in the great Canadian Shield, which is lacking in commercial coal deposits but is rich in water-power resources. This Precambrian formation, which forms a wide belt around Hudson bay and in which many metalliferous ores are found, was &apos;subject to severe glaciation in a recent geological period, so that its river systems are comparatively young and are characterized by numerous lakes joined by short reaches of fast water, rapids, and falls which offer frequent opportunities for power development. The western Cordilleran region, which also is important in mining, has abundant water power. The accompanying geological map (Figure 2), prepared by the Geological Survey of Canada, shows the great extent of the Precambrian and Cordilleran regions and may be compared with the map of water-power sites to show the high incidence of water-power resources in these potential mining areas in which important mineral discoveries have already been made.

Jan 1, 1949

By H. G. Doll

THIS paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simple and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, timesaving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given.

Jan 1, 1944

Four slag types covering the range of Fe-Ca-Si-O compositions and two iron blast furnace slags were melted at 1300 °C and doped with 1% of arsenic, antimony, cadmium, zinc and chromium. The melts were either slow cooled or quenched and the solidified slags were leached according to TCLP procedures. The morphology of the solidified slags was characterised using XRD, optical and electron microprobe techniques. Theoretical considerations showed that the capacity of the molten slag to hold the above toxic elements depended upon slag basicity and this was confirmed in practice. The experiments showed that the leaching of the toxic elements was a function of surface area and the phases present, both of which were affected by the mode of cooling. Iron silicate slags produced in nonferrous smelting operations and blast furnace slag from ferrous smelting operations both show promise of being suitable media for immobilising low levels of toxic elements and complying with current regulatory requirements.

Jan 1, 1994

By Alyse Munro Hindley

The increasing negative public opinion toward blasting has led to stricter regulations and increased costs. This paper outlines alternative methods of rock excavation and the safety regulations and certification required by blasting professionals. Most importantly, however, it showcases the benefits and accomplishments that controlled blasting bring to society, giving the public a better understanding of the necessity of blasting in modern society.

Jan 1, 2015

By Mitchell D

In recent years the need to provide increased ventilation to improve environmental conditions rather than to dilute firedamp has led to increasing interest in the use of recirculation. Present UK mining law prohibits recirculation in ventilation, but it has been permitted selectively by exemption granted by Hm Inspectorate of Mines and Quarries. The conditions of use imposed by these exemptions to safeguard the safety and health of miners are examined in detail, dealing separately with primary and auxiliary recirculation systems.

Jan 1, 1988

By L. P. Lamprecht

Traditionally, South African shaft sinking operations have used electric detonators for the initiation of blastholes. Globally, the trend in shaft sinking is to use the shock tube and detonating cord (STDC) initiation system, with value adding benefits. In pursuing this global trend, Cementation Mining of South Africa in partnership with SMX have ventured the STDC route. This paper explores the work carried out to date, and identifies a number of benefits to be gained by using the system.

Jan 1, 1999

By G. Winkel

Safety conditions in industry have greatly improved over time. However, around the world, in Canada, and in each province or territory, people are still the victims of serious industrial accidents. The increasing safety of people at work then continues to be an imperative in industry today.<p> So how do we achieve a workplace where no one gets hurt? Well, in simple terms, folks need to be protected from unplanned exposures to equipment or energy sources that can do harm. If you think about it, all of our efforts in loss management and safety should then be directed toward avoiding these uncontrolled events. And it works! Our safety performance over the years has enjoyed tremendous improvement due to this support for loss management and safety. We now explore best practices toward achieving that next step in safety improvement.<p> As shown following, a large combination of loss management activities act together to support safety performance. Many of these activities are interrelated and some people have described them as the ?inputs? into an approach or program for achieving safety. Using this description, it follows that the ?outputs? of the program are some of the advertised measures of safety we see around us today, such as injury frequency rates. <p> It is asserted that a leadership focus to regularly measure safety and loss management activites (so-called ?inputs?), as a basis for taking supportive actions to ensure their effectiveness, is the basis for safety results (so-called ?outputs?) that consistently achieve high standards of excellence.<p> The concept of managing input activities, as enabled by effective measurements, can significantly act to transform our focus and priorities in the workplace. Supporting input activities like strategies, plans, or procedures with our best efforts will get us to our intended goals. Tracking outputs alone will not.<p> Safety and production have traditionally been cast as competing objectives. When both objectives are mutually supported and considered, however, people will invent ways of doing work that support both safety and production, and any other business parameter. When done right, innovation through meaningful involvement of affected people in the workplace will support safety excellence in a manner that in turn improves business efficiency overall.<p> For a workplace to be safe, it then requires everyone?s help and participation to make it happen, a collaborative effort by management, leaders, and frontline folks with the power and responsibility to take appropriate action at every level in the organization. In this way, everyone becomes a leader in safety.<p> The achievement of commitment to loss management input activities by folks in the workplace is the basis for attaining safety excellence. A workplace founded on commitment supports a safety culture with a vision for safe work performance at outstanding or world-class levels of achievement.<p> One may ask if injury incidents will be eliminated with this commitment and focus on workplace safety? Well, despite our best efforts in this area, there is never a guarantee that things can?t go wrong. We are simply not perfect. There remains in our workplace complexities and unanticipated risks that can have disastrous consequences if not managed at every moment. And when it goes wrong, we need to know we?ve truly tried our best, and now we have more to learn so we can get even better. <p> That?s the challenge represented by the safety imperative, a challenge to take safety performance that next step, a fulfillment of our commitment to the moral obligation we have to each other?s safety. It?s an effort that will continually raise the bar of world-class safety performance achievement for future generations. It?s a legacy we can be proud to be part of.

Sep 1, 2004

By G. Winkel

"Safety conditions in industry have greatly improved over time. However, around the world, in Canada, and in each province or territory, people are still the victims of serious industrial accidents. The increasing safety of people at work then continues to be an imperative in industry today. In addition to protecting people, safety has been shown to make good business sense in any industry.The road to safety improvement is built on establishing a culture of safety that forms the basis for how work gets done in a company. Most importantly, an effective safety culture is built on the full engagement and participation of workers and leaders alike, who share in a vision for safe work performance where “no one gets hurt” and “everyone is a leader in safety.”Let’s learn together on how we can make a safety culture happen. The resulting bias for safety will ultimately save lives, and fulfills our moral objective to strive for safety excellence. IntroductionWe have the good fortune of living in democratic countries where freedom and the value of human life are key beliefs. These beliefs translate into the moral obligations and laws that we value and uphold in our society and life today.A minesite or workplace is simply a necessary part of our society where people earn a living. It is a place where our moral obligations and laws equally apply, a place where human life is of ultimate importance and value. In the early years of industry, this value has not always been evident. Take this description of a tragic accident reported in a coal mine on December 8, 1879:“Oliver Thompson, shaftman, aged 35— While taking wooden partitions out of a ventilation shaft, he fell off the work platform a distance of 100 yards, there did not appear to be anything unusual to account for this accident.”"

Jan 1, 2004

By Richard Snyder

Secretariat of the Coal Mining and Mining Executive Committees&apos; of the National Safety Council (NSC) and Manager of the memberships to both Mining Sections; Senior Consulting Safety Engineer, NSC; member of several committees for consensus Standards of the American National Standards Institute (ANSI); a Certified Safety Professional (CSP) of the Board of Certified Safety Professionals of the Americas, Inc. and a chief proctor for CSP testing and certification procedures, et al. It appears that the tunneling trade is merging into its own renaissance for the decade of the 1970s&apos;, and most likely on past the year 2001. Federal interest in underground excavation, and more specifically, rapid excavation expertise has been on the upswing since the latter part of the 1960&apos;s, mainly due to the pressing national needs for more raw materials based on the rise for material goods and the projective gloom of possible power shortages. On the pure tunneling side the national needs encompass, in the mainstream of priorities, rapid transportation and water supply excavation as the two top contenders. For instance, the estimates for tunnel mileage for the period 1968-1975 are:(1) Subways---85 miles Urban Highways--- 123 miles Intercity Highways---210 miles Water Supply Routes---528 miles at a total of 946 miles of tunnels. The estimated cumulative underground excavation demand in dollar amounts for the period 1970-1989 are:(1) Construction Oriented Demand--- $35 billions Mining Oriented Demand---$34 billions (which includes the coal-oriented demand on the order of 26 billions.

Jan 1, 1997

By A. H. Ransom, M. E. Robb

The Salmita Gold Mine is located 240 air kilometres northea t of Yellowknife on the east shore of Matthews Lake. Salmita is one of several gold showings which are regionally associated with the steep easterly dipping contact zone between mafic, intermediate and fe lsic volcanics to the west and overlying finely laminated argillaceous sediments to the east. The volcanic assemblage forms a narrow 2 m to 7 m wide north to northwesterly trend ing Belt of Yellowknife Supergroup Archaen greenstone rocks. The contact zone exhibits exhalite character and the increased sulphide content provides a di stinct VLF-EM , IP/Resisti vi ty and/or magnetic signature. Gold occurs at or near this contact in three main settings: associated with si liceous vein-like structures; with finely disseminated sulphides within ericitic altered upper fe lsic tuffaceous unit ; or with quartz in narrow shear zones within the overlying sediment . The B-Vein is of the former type with free mi ll ing gold occurring within a highly sil iceous zone having an average widtn of 1.69 m. Alteration is intense within the immediately su rrounding host lithologies and includes the development of si lica, carbonate, sulphide, sericite and chlorite with minor graphite, epidote. tourmaline and scheelite. The mineable zone above the 4th level (-200 m) ha an average strike of 160 m and is divided into three south plunging ore shoots separated by the regional Salmita Shear Zone in the south and by a low-grade structural hiatus in the north. Production from the B-Vein commenced in August 1983 based on a diluted in situ ore reserve of 140,000 t grading 26.6 git Au . As of December 31, 1985, a total of 131 ,537 t grading 27.8 git Au have been mined at a ra.te of 160 t per day and a 96.4 percent recovery, to produce 3,522 ,000 g (113,227 ounces) of gold . Current (January I, 1986) reserves total 45,500 t grading 37 g/t Au down to the 10th level (-500 m) .

Jan 1, 1986

By A. R. Chambers

Malagash received its name from the Indians many years ago on acco.unt of its turbid (milky) waters, although,&apos; the red men did not appreciate the significance of this turbidity, and were, of course, entirely ignorant of the crystal beds of pure salt that lay beneath their feet. The salt lake of the Mississippian, or Lower Carboniferous period, in which these beds occur, was apparently a large one, for there is evidence of its existence at intervals all the way from Sydney, Cape Breton, to St. John, New Brunswick, 300 miles as the crow flies, and there is no knowing what its other dimensions may have been, as much of this horizon is now buried on the one side beneath the waters of the Gulf of St. Lawrence, and on the other underneath the Atlantic ocean. About midway of the area and underlying the counties of Colchester and Cumberland, there occurs a synclinal basin of which the Malagash salt outcrop forms only a small portion of its northern limit. This basin has been described very fully by A. C. Hayes. (1) The operations carried on at Malagash since Hayes wrote his report have brought to light very little in the way of new geological data, except to confirm his pre-dictions as to the probable faulting of the salt strata, and the effect which these faults would have on mining operations.

Jan 1, 1924

By W. M. Weigel

SALT production in Louisiana and Texas at the present time is entirely from salt domes of the interior and coastal groups. Before and during the Civil War salt was recovered from numerous salines and salt springs by evaporation in open &apos;kettles. The location of these in nearly every instance was near what is now known to be a salt dome, and the source of the salt in the salines and spring waters was that in the salt core. The tops of many of the shallower domes have been subjected to erosion1. The discovery that the salt occurred as large masses of rock salt in the form of domes was made in May, 1802, at Avery Island, La., by John Marsh Avery, grandson of the original owner, John C. Marsh, who built the old salt works in 18122. The first shaft for mining was sunk on the Avery dome in 1867 by Chouteau and Price. It was 90 ft. deep, about 58 ft. being in solid salt. It was abandoned in 1870. There are three general groups or fields of salt domes; interior Louisiana in northern Louisiana, interior Texas in northeastern Texas, and the coastal domes nearer the Gulf Coast and extending from the Mississippi River to the Rio Grande. This last group contains by far the greatest number of domes. As many of the coastal domes especially are prolific producers of petroleum and a few of sulfur, their geology has been intensively studied and fully covered in the literature. The depth to the top of the salt varies from near the surface, where shallow ground waters have dissolved the salt to just below recent deposits, to several thousand feet, where the depth has been estimated only by geophysical methods. The diameter of the salt core varies from less than ½ mile to over 2 miles. Only domes where the salt is compara-tively near the surface have been developed for commercial salt. Three deeper domes, which will be described later, have recently been developed or are in process of development, as a source of brine for chemical use.

Jan 1, 1935

By Y. Yang, M. Zhang, X. Xia, S Shi, Z. Shen

A stepwise arrangement of flotation cells is the most common layout of a flotation circuit in the mineral processing industry. In such a design, slurry flows from upstream to downstream by means of gravity, and the middling products are returned to previous stages by pumps. This paper will introduce an alternative solution in which the forced-air and slurry-induced flotation cells are adopted so that all the flotation cells can be placed on the same horizontal platform and no pumps will be needed for middling product transferring. The technology of the forced-air and slurry-induced flotation cell will be described in detail, including unique features, the working principle and the related fundamental problems. The comparison of capital investment, operating cost and metallurgical performance will be made between the conventional stepwise arrangement and the samelevel arrangement technology based on industrial practice. Keywords: Forced-air and slurry-induced flotation cell, same-level arrangement, stepwise

Jan 1, 2020

By G. Derge, W. Peifer, J. H. Richards

INTRODUCTION A WIDE variety of metallurgical defects in steel have commonly been attributed to the presence of excessive amounts of hydrogen. These defects include flakes in rails and forgings, cracks in welds, and blisters in enameled ware. They have been related to hydrogen largely by circumstantial evidence because the proper sampling and analysis of steel for hydrogen has been known to be difficult and because no general agreement has existed with regard to the relative suitability and accuracy of available methods. The need for a direct approach to these problems has been widely recognized. This general situation has been well described in the publications of the British Committee on the Heterogeneity of Steel Ingots,1 and current approaches to the problem were reviewed in a recent symposium of the AIME.12 The plans described by the present authors at that meeting have now matured satisfactorily and will form the basis of this paper. The principle object of this paper will be to describe the methods of sampling and analysis which have been developed and to illustrate the usefulness and limitations of these methods by citing their application to a specific problem. The first problem selected for investigation was the behavior of hydrogen in rail steel. This was chosen because the occurrence of shatter cracks in rails has received a great deal of study over a long period of time. The defect can be controlled by the expensive procedure of slow cooling. However, it may be hoped that a better understanding of the factors influencing the hydrogen content of rails will lead to a more efficient control of this problem. Rails provide a good starting point for a more general study of hydrogen in steel because they provide a cross section large enough to develop cracks, yet small enough for convenient handling and sampling. Rails were also selected because they are made from plain carbon steel and it was felt that the initial work should not be complicated by the effects introduced by alloying elements. The considerations which determined the original planning of this study should be reviewed. The inherently complex nature of most hydrogen problems requires that a large amount of data must be collected for any particular case. This in turn means that any analytical procedure should be as rapid and simple as possible. The same objective of speed is indicated by the fact that it may finally become desirable to use hydrogen analysis in process control. It is also known that hydrogen is highly fugitive and that any procedure which facilitates early analysis of the sample without prolonged or irregular storage has distinct advantages. The most important previously reported methods of analysis may be classified into three general groups: (I) Vacuum fusion. (2) Vacuum extraction (without melting). (3) Total combustion.

Jan 1, 1948